Tool



Patented Nov. 30, 1943 TOOL Donald H. Montgomery, West Hartford, Conn,

assignor to The New Britain Machine Company, New Britain, Conn, acorporation of Connecticut Application March 14, 1941, Serial No.383,321

1 Claim.

My invention relates to a tool for lathes and the like.

It is an object of the invention to provide an improved form of toolblade.

It is a more specific object to provide a symmetrical tool bladeproviding for the maximum number of interchangeable cutting edges.

It is another object to provide an improved tool blade of maximumstrength properly relieved so as to clear the work.

Another object is to provide an improved form of tool holder.

Other objects and features of the invention will be pointed out or willbecome apparent.

In the drawing which shows, for illustrative purposes only, a preferredform of the invention-- Fig. 1 is a top plan view of a tool and holderillustrating features of the invention;

Fig. 2 is a view in side elevation of the parts shown in Fig. 1;

Fig. 3 is a fragmentary view similar to Fig. 2 but viewed from theopposite side;

Fig. 4 is an enlarged fragmentary sectional view taken substantially inthe plane of the bolts of Figs. 1 and 2; and

Fig. 5 is an enlarged view of the tool blade in end elevation.

My improved tool blade is particularly, though not exclusively, adaptedfor use as a cut-off tool. The tool comprises an elongated blade,designated generally 6. In the preferred form the blade 6 is symmetricalin transverse section and is widest at the edges 1 and 8. The tool isrelieved at opposite sides adjacent the edges 1 and 8, as is indicatedat 99. Such relief does not extend to the center of the tool, as wouldbe the case in a hollow ground tool, but, on the contrary, such reliefor inwardly tapering section terminates a short distance inwardly fromthe edge, say along the line Ill. The opposite sides llll of the bladeinwardly of the relieved sections are preferably parallel to each otherand thus a blad having an extremely rigid section is provided.

Since the tool blade is of symmetrical section it may be ground atopposite ends in generally fish-tail form, so as to provide cuttingedges l2l3 at one end and duplicate cutting edges I l-I5 at the oppositeend. When so ground the blade possesses four cutting edges, which may beused one after the other before the blade need be removed forresharpening. The blade should be of a width, that is, of a height asviewed in Figs. 2 and 3, somewhat greater than the radius of the bar tobe cut off, in order that the tool will clear the work properly; that isto say, when the cutting edge I2 is being used, the lower side of thebar should be higher than the lower relief line In as viewed in Fig. 2.With a blade of the proper height the tool will fully clear the end ofthe bar and the piece part, since the sides Il-l l of the bar define anarrower section than the cutting edge I.

My improved tool holder includes means for receiving the tool andsecurely clamping the same thereon. In the preferred form the toolholder is provided with a slot I 5' of a width to properly receive theblade. The blade is clamped in the slot by improved means, preferably inthe form of a bolt l6, slidable in a hole I! through the holder. Thebolt is provided with a clamping projection and, in the form shown, suchprojection is formed by cutting a notch IB transversely in the bolt, andthe hole I! in the holder intersects the slot I5, whereby a blade passedendwise into the slot will pass through the notch ll! of the bolt. Theclamping edge of the notch I8 is preferably under cut, as indicated atl9, so that the blade 6 is engaged inwardly of the edge, as shown at 20.Thus the outer edge of the blade 6 is not forcibly engaged by theclamping surface and is therefore not marred thereby. If desired, theslot IS in the holder may also be undercut or relieved along thelongitudinal sides of the bottom, as shown at 2|,

'so that the side edges of the tool will not be marred. However, it isnot so necessary to undercut or relieve the slot, since the blade has avery extended bearing surface in the slot and is not so likely to bemarred by the slot as it would be by the side of the slot in the boltI6. However, one or both of the undercuts l9-2l may be dispensed withand those surfaces made to conform to the shape of the adjacent bladeparts so as to fit flat thereon and thus avoid stresses that mightotherwise be set up when the bolts are drawn up. The bolt l6 has a nut22 threaded thereon for drawing the bolt in to clamp the blade in place,as will be clearly understood. In the preferred form two securing boltsare provided, one at each edge of the blade 6, as will be clear fromFigs. 2 and 3. These bolts may be and preferably are duplicates of eachother and ghetdescription already given will suflice for both When it isdesired to remove the blade or adjust it lengthwise in the holder it isnecessary only to back off on the nuts 22, so as to release the blade,after which it may be freely moved longitudinally in the holder orremoved entirely therefrom. It will be seen that my improved blade isprovided with multiple edges and a cutting edge locating surface. Thuswhen the blade is replaced it almost automatically assumes the correctposition.

The tool herein disclosed, while particularly useful as a cut-off tool,is Well adapted for use as a tool slide tool in a combination as setforth more particularly in my application, Serial No. 383,320, filedMarch 14, 1941, wherein the tool slide tool is designed to cut insidethe center line of the spindles of a multiple spindle machine, and is soplaced that the major force of the cut is more or less toward the stemcarrying the tool slide rather than across it.

While the invention has been described in considerable detail and apreferred form illustrated, it is to be understood that various changesmay be made Within the scope of the invention as defined in the appendedclaim.

I claim:

In a tool, an elongated tool blade substantially symmetrical intransverse section, said blade being Widest at its edges and relievedinwardly of its edges at opposite sides, said blade having asubstantially V-shaped symmetrical slot cut in the end thereof, for thepurpose described.

DONALD H. MONTGOMERY.

